Pepper

In the summer of 1965, a female Dalmatian was stolen from a farm in Pennsylvania. Her story changed America.

First, Ivan Pavlov would sever a dog's esophagus and sew the loose ends to its throat, leaving a pair of adjacent holes that connected, by separate passages, to its mouth and stomach. Then he'd slice through the dog's abdomen, carve a hole in the wall of its stomach, and stitch open another permanent wound.

The dog, left hungry from the night before, would be harnessed to a wooden stand and presented with a bowl of raw meat. No matter how much it ate, it never got full—the dog chewed and swallowed, but the masticated meat would erupt from its esophageal opening and dribble back into the bowl, whereupon the dog would lap it up all over again. In the meantime, a glass tube attached to the animal's stomach opening allowed its gastric secretions to drip into a collecting bottle, so they could be filtered, analyzed, and sold to the public as a remedy for dyspepsia.

As historian Daniel P. Todes writes in Pavlov's Physiology Factory, these thrice-perforated animals enabled a new approach to science—the chronic experiment—and a series of discoveries about the nervous control of digestion for which Pavlov won the Nobel Prize in 1904. (At the time of the award, he was just beginning to study how animalslearned to salivate at the sound of a buzzer.) * In 1935, just before his death, Pavlov approved the design for a monument to his canine test subjects, erected on the grounds of the Institute of Experimental Medicine in St. Petersburg, Russia. A bronze plaque on one side depicts the dogs on laboratory tables, tied to their wooden frames with their fistulas open. "We must painfully acknowledge that, precisely because of its great intellectual development, the best of man's domesticated animals—the dog—most often becomes the victim of physiological experiments," he had written in 1893. "The dog is irreplaceable; moreover it is extremely touching. It is almost a participant in the experiments conducted upon it, greatly facilitating the success of the research by its understanding and compliance."

No one can say exactly how old Pepper was in the summer of 1965, but every member of the Lakavage family remembers her gentle disposition. There were plenty of other dogs racing around their farm at the bottom of Blue Mountain, but the Dalmatian named Pepper—trim and affectionate, pelted with splotches of black—was always Mom's favorite.

Julia and Peter Lakavage

Julia Lakavage preferred to take in strays, but she made an exception when she saw Pepper at the decrepit Spatterdash kennel a few miles down the road. Julia and her husband, Peter, lived on 82 acres in the hills above Slatington, Pa., two hours due west of New York City. Peter had a job with Bethlehem Steel; Julia had polished shells there during the World War II, but by the 1960s she was working the night shift as a nurse for the Good Shepherd Home in Allentown. They had four daughters—Star, Carol, Kathy, and Peggy—and a 7-year-old grandson named Michael.

Pepper loved a car ride, and some nights Julia would take her along to the hospital in Allentown. If Julia were the only nurse assigned to the floor, she'd bring the dog on her rounds of nursing home residents and handicapped orphans. The patients loved it, remembers Star. They would call for Pepper as soon as they heard her paws click-clacking along the linoleum hallway. One day, Julia promised, she'd buy "Nurse Pepper" a little white hat.

But Pepper didn't come to work with Julia on the night of Tuesday, June 22, 1965. Sometime that evening, the Lakavage children let Pepper out onto the back porch for her usual evening stroll. When they opened the door half an hour later, the dog wasn't there. "Pepper always came, no matter what," says Michael. "You'd go to let her back in, and she'd be laying on the porch, waiting." For the first time that any of them could remember, Pepper was nowhere to be seen. Michael remembers standing in front of the house, calling into the darkness.

By the next morning, the Lakavages knew for sure that Pepper was gone.

Over the next few days, Julia mobilized her family in a desperate search for the missing dog. According to a short version of the incident that was published five months later, improbably, in the pages of Sports Illustrated, "all during the following week, a heartbroken Mrs. Lakavage advertised and hunted for her dog." Indeed, no one in the family had ever seen Julia so upset. ("Dogs are like family members," she would later tell a newspaper reporter, "children that don't grow up.") The Lakavages fanned out through the woods and along the dirt road that ran past the farm. They checked with the neighbors up the hill and drove to the top of Blue Mountain to call for Pepper from the ridge under the power lines. Julia posted signs and telephoned everyone she knew.

Michael assumed that a neighbor had run over Pepper with a car—there was kid up the road who messed around with muscle cars—but Julia talked to someone who had seen a man loading a Dalmatian into the back of a truck near their farm.

For years, animal welfare groups had been warning of nighttime forays by pet snatchers in unmarked vans. Stolen dogs, they said, were being sold to laboratories and subjected to painful experiments. In 1961, Walt Disney had released 101 Dalmatians—a hugely successful film about pet theft—and the Humane Society of the United States had begun to look into a network of illegal animal dealers operating across Pennsylvania and Maryland. Navy veteran Frank McMahon led the investigation and hired Dec Hogan, a rough-and-tumble nightclub owner, to pose as a dealer in the field. Along with another investigator, Dale Hylton, they began to stake out the rural auctions where stray animals were traded before being shipped off to research laboratories in big cities. The team devoted much of its energy to a notorious Amish market down in Lancaster County, known as the Green Dragon.

Named after a Chinese restaurant on the Atlantic City, N.J., boardwalk, the Dragon had been operating in the town of Ephrata since 1932. (It's still open.) Fridays were auction days, with sales of livestock running all afternoon. The small-animal sale started by 7 p.m.: An auctioneer would set up in the middle of a rectangular pen, about 20 feet by 40 feet, surrounded by bleachers. Crated dogs and cats were rolled inside one by one and put up for bidding.

Hogan remembers thousands of people at the market, Amish vendors selling pies and cookies, and the animal dealers—"grass-roots kinds of guys, doing it for a six-pack of beer"—carting in stray dogs for sale. The winter before Pepper disappeared, investigators had watched one dealer purchase hundreds of dogs at the Green Dragon and pack them into his truck in chicken crates. When he returned home the next morning, the police were waiting; he was arrested for cruel treatment of 7,000 animals on his farm and paid a $67 fine.

Likely at the suggestion of her local SPCA, Julia Lakavage decided to investigate the Green Dragon market for herself. On Friday, June 25, three days after Pepper vanished, Julia put her daughter Star and grandson Michael into the backseat of a finned, brown '60 Ford Fairlane with a green interior and drove an hour or so down to Ephrata.

Star, who was 14 at the time, remembers rows of wire crates at the Green Dragon auction. They were stacked two and three on top of one another, filled with dogs and goats, and left out in open areas without shade. The Lakavages visited at least one more auction in the days that followed. But Pepper was nowhere to be found.

Jack Clark

Almost 200 miles away, in the Pennsylvania mountains near the Maryland border, a 77-year-old outdoorsman named Jack Clark was getting ready for his weekly animal swap. Jack was burly and gregarious, with a generous gut and a bald head. He lived out in the woods of Black Valley and kept by his house an extensive menagerie of woodland and other critters. There were pet raccoons and caged skunks, penned-up groundhogs and captured foxes. But above all, there were dogs.

Jack made his living as a dogcatcher, and he kept hundreds of his quarry boxed up by the creek out back. His grandkids remember seeing big dogs and little dogs on the property, mutts and purebreds, golden retrievers and Dalmatians. "I remember laying upstairs in bed at nighttime," recalls his grandson Terry, "and falling asleep to the sounds of the dogs barking."

Everyone in town knew Jack and his big, green pickup truck, with the wood-framed animal cab loaded on the back. When he was in the area, he'd stop in at Sponsler's Superette every few days to pick up meat scraps for the animals. Jack would come and go, disappearing one day and returning later in the week with 10 or 15 dogs in tow.

There was talk among the locals that Jack wasn't just picking up strays, that he'd steal dogs out of people's backyards and sell them off to medical labs in Philadelphia. But the county dog law enforcement officer—Fred Sponsler, who owned the Superette where Jack did his shopping—appears not to have filed any charges. Later on, Terry Clark and his sister Kay would conclude that their granddad had been carting live cargo to research labs in Harrisburg.

Jack's friends and fellow dealers would converge on his property every weekend to trade horses, goats, cats, and dogs while their children played on the ponies out back. It's impossible to know whether Jack Clark made a dogcatching expedition up to Slatington in June of 1965, but, one way or another, Pepper seems to have ended up at his weekly swap in Black Valley, on Sunday, June 27, five days after she disappeared.

By Tuesday, June 29, one week after her disappearance, Pepper was in the hands of Jack's good friend Bill Miller.

If you lived in Slatington, or Allentown, or just about anywhere in the region, the summer of 1965 would have been long and miserable. A four-year drought, made worse by a run of scorching, cloudless days, pushed New York City's reservoirs to half-capacity. Golf courses dried up, the rhododendrons and azaleas crumpled at the city's botanical gardens, trains and buses went unwashed, and the mayor proposed tapping the Hudson River for drinking water.

In all that nasty summer, no single day was more vile than June 29. The temperature reached 95 degrees in the afternoon, the humidity 50 percent. The New YorkTimes pronounced that an "asphalt-softening, brain-fogging heat" had overtaken the city. And somewhere on the 170-mile stretch of Route 78 that runs from Harrisburg, Pa., to the New York state border, 18 dogs—including two boxers, a Weimaraner, several mixed collies, and a pair of female Dalmatians, one of them Pepper—were locked in a small enclosure on the back of Bill Miller's pickup truck, crammed inside with a pair of goats.

Bill Miller ran Broken Arrow Kennels out of McConnellsburg, a half-hour's drive east from Jack Clark's place in Black Valley. Like the other dealers in Clark's circle, Bill was an older guy—and a regular target for Humane Society investigators. In February 1964, Dale Hylton had visited his farm in the guise of a buyer for a Long Island hospital, successfully placing an order for 170 research dogs. The unsanitary conditions he found there were grounds for a search warrant, and he later returned with a constable to file charges of cruelty to animals.

Miller would have another run-in with the authorities at the end of June 1965. He seems to have set off from McConnellsburg on Tuesday afternoon, a week after Pepper disappeared from the Lakavage farm, and made his way across the Susquehanna River on Interstate 81. From there he would have had a straight shot through Allentown and into New Jersey. But a few hours later, with Miller just moments away from crossing the New Jersey border, the local police in Easton pulled his truck off the road and asked to look in the back.

Distressed by the sight of 20 animals huddled in a cab with little ventilation, the cops wrote out a pair of tickets—$74 for overloading the vehicle and $10 more for "cruelty in transport"—and handed over the dogs and goats to the county animal shelter. Miller said he was on the way to Arthur Nersesian's research holding facility in High Falls, N.Y., and that he'd be back the next day to pick up his haul with a bigger truck. The shelter's proprietors agreed to release the animals if and when Miller could deliver the proper bills of sale. They photographed the dogs that night.

Miller returned to Easton Wednesday morning, as promised, with money to pay his fines and a larger vehicle. The shelter turned him away—the new truck had no air vents in the back, and he hadn't yet provided any documentation for the animals.

At 9:15 that evening, Miller showed up at the shelter once more—in a third, still-larger truck, a bundle of receipts in hand. The staff at the shelter went over the sales slips and, having stalled as long as they could, reluctantly turned over the cargo. Months later, Frank McMahon of the Humane Society would tell Congress that the receipts may have been forged.

The next day, the Allentown Morning Call ran a story about the episode, under the headline "18 Dogs, 2 Goats Seized; Ownership Proof Sought." By that point, though, Pepper was back on the road.

Peter Lakavage knew his wife was frantic, but there was only so much he could do from a hospital bed in Allentown. Sometime in late June, Peter had suffered a heart attack, one of several he would have over the next few years. (The final, fatal blow came in 1969.) On the morning of Friday, July 2, Peter flipped open a copy of the Morning Call in his hospital room and saw an article following up on the previous day's story: "20 Animals Resume Their Trip." Among the dogs listed in the article were two purebred, female Dalmatians. Peter climbed out of bed and called his wife.

Julia dialed the Easton shelter as soon as she got the news. One of the impounded Dalmatians had been 8 months old, the shelter's proprietor told her, and the other was an adult. Julia could try to identify Pepper from the photographs taken Tuesday night, but those weren't due back from the developer until later in the afternoon. Meanwhile, the county SPCA had already gotten in touch with animal activists in Washington, D.C., and in upstate New York, where Miller said he was taking the dogs.

Within the hour, Julia had her grandson Michael and daughter Star in the back seat of the Ford Fairlane and Carol in the front, and they set off on the 130-mile drive to High Falls, N.Y. Star remembers stopping at pay phones along the way so her mom could arrange meetings in New York and make sure there was someone to cover her nursing shift at Good Shepherd.

The family arrived that afternoon at an upper-middle-class neighborhood in Ulster County. Star remembers the well-appointed houses and manicured gardens: "Here we were, this little family from god-awful nowhere on some farm," she says, "and these people from really nice homes were talking to my mom. … I thought, 'Holy cow, we're just looking for our dog—we just want to know what happened to our dog.' " Having conferred with members of the local humane groups, Julia drove out in search of the Nersesian farm.

At 2 that afternoon, she arrived with her children at the New York State Police station on the highway near Kerhonkson. Julia described her search for Pepper and asked for help. Would the troopers please come up to the farm on Clove Valley Road?

Arthur and Helena Nersesian in 1963

Arthur Nersesian was 55 years old, an avid boxing fan, and a retired New York City cop. For two decades he'd run down hoodlums out of the 3rd Precinct in Chinatown, but in 1957, he packed up his place in Queens and moved the family to a plot of land upstate, with a Dutch stone house, a couple of grain silos, and a gambrel-roofed barn.

The property was ringed with "No Trespassing" signs, and locals remember an alarm that went off whenever a vehicle entered the driveway. Nersesian had other ways of keeping out strangers. According to the Morning Call, he'd already filed a $2.5 million lawsuit against a New York SPCA unit for allegedly entering the farm without permission.

The state troopers on Route 209 may well have known the Nersesians were selling dogs for research down in the city. (The family is still proud of the farm's contribution to the early heart-transplant studies in Brooklyn.) But there wasn't much the police could do when the Lakavages arrived that afternoon. A trooper informed Julia that a search would be impossible without a warrant, and there was no way to get a warrant without hard evidence that Pepper was on the premises. "She wasn't going to go out there," the trooper said later. "She was kind of upset because she was pretty attached to the dog."

With no way to get onto the Nersesian farm, Julia turned the car around. By Friday night, the family was back home in Slatington. Reporters called the house that night, but Julia was reluctant to discuss the case, fearing that too much publicity would put Pepper's life in danger. "It's just a long-shot chance," she said, finally. "I didn't mean to make trouble, I only wanted a chance to look at the dogs to see if my dog was there."

Fay Brisk

At the offices of the humane societies and other animal welfare groups in Washington, 47-year-old Fay Brisk was known as the "dog dealers' Madame Defarge." A former member of the Women's Army Corps, Brisk had gotten kicked out of the military for marrying a fellow officer without permission, and took a job as an information specialist with the government. She was still on the federal payroll in the 1960s, detailed to the White House with the Small Business Administration. On weekends, though, Brisk would sometimes travel back to Berks County, Pa., where she grew up. There she would pursue her decadeslong obsession with animal welfare.

Brisk's hometown was just 20 miles from the dog-and-cat auctions of the Green Dragon, and she'd worked as a reporter for the Reading Eagle and the Philadelphia Record. Over the years she cultivated a rich network of sources and friends among the animal traders.

One of those sources tipped off Brisk about Julia Lakavage and the search for Pepper. She may have been following the events from her home in Georgetown, or it's possible she traveled to High Falls, N.Y., to meet Julia in person. In any event, she learned on the afternoon of July 2 that the Lakavages had been denied entry to the Nersesian farm and that the local authorities were reluctant to deliver a search warrant. She decided to take the matter to the Capitol.

Brisk called her friend Christine Stevens, founder and chief lobbyist of the Animal Welfare Institute. Stevens was elegant, cultivated, and as well-connected as anyone in Washington. Her husband, Roger, had worked closely with Presidents Kennedy and Johnson; a few months later, he would be tapped as the founding chairman of the National Endowment for the Arts. The Stevens were also close with a patrician Pennsylvania senator named Joe Clark. At Christine's urging, Clark had introduced a series of unsuccessful laboratory-animal-care bills dating back to 1960.

Sen. Clark had all but shut down his office for the July 4 holiday. Weekend coverage fell to a junior staffer named Sara Ehrman. She answered when the call about Pepper came in late on Friday afternoon. Ehrman would eventually become a major player in the Democratic Party, a board member of the American Israel Public Affairs Committee, and a close friend to the Clintons. But in the summer of 1965 she was a peon in Joe Clark's office. "I don't even like dogs," she says now, with renewed pique. But she passed on the message, and word came back from the senator: "Do what you're supposed to do for Christine."

Ehrman looked up the House representative for Ulster County, N.Y., and found Joseph Resnick—a crusading liberal who had just defeated a 14-year incumbent in an overwhelmingly Republican district. There couldn't have been a man in Congress more different in style from Joe Clark. Resnick was a high-school dropout, a former television repairman who had made tens of millions of dollars by inventing the preassembled, rotating TV antenna. According to the New York Times, the stocky, cigar-smoking business executive rode around in a "telephone-equipped gold-color Continental." His stint in Washington was brief—Resnick died of unspecified causes in a Las Vegas hotel room in 1969—but unusually productive. During four years in office, he worked up a distinguished résumé on civil rights and agricultural reform, and patented new machines for blow-molding and decorating plastic containers.

Resnick was eager to intercede for the Lakavages and their missing dog. He placed a call to Arthur Nersesian that same afternoon and made a personal request that Julia be allowed to check the premises. Not without a search warrant and charges in writing, the ex-cop replied.

Their exchange was described in the next day's Morning Call: "Stolen … Sold? Trail Leads to N.Y.—Love for Dog Stirs Two States."

Resnick was outraged. He contacted the FBI on Friday evening to find out if moving stolen dogs across state lines was a federal crime, and then he pressured the Ulster County district attorney's office for a search warrant. But Nersesian held firm, and no one set foot on his farm to look for Pepper.

There was a fog in Allentown on Monday, July 5, and thunderstorms delivered some much-needed rain. At some point during the holiday weekend, Fay Brisk had called the Pennsylvania state troopers, and soon the dog law enforcement officer down in Everett, Fred Sponsler, was investigating Pepper's whereabouts as well. Bill Miller told the authorities that he'd gotten the Dalmatian bitch from another friend of Jack Clark's named Russ Hutton, who'd bought the dog off Jack Clark. Sponsler said he couldn't find Clark to confirm the story, but he nevertheless concluded that Clark had gotten the dog in question from "an Altoona man who got rid of it for eating chickens."

In any case, Bill Miller revealed one more crucial detail. He'd never actually driven up to Nersesian's farm in High Falls, he admitted to the police. Instead, he'd loaded up his truck at the shelter in Easton on Wednesday night and gone straight into Manhattan. On the previous Thursday, June 30, he sold a dozen dogs and both goats to Einstein, St. Luke's, and Columbia hospitals. And then he drove up to the Bronx and unloaded the rest of the animals—including both Dalmatians—to Montefiore Hospital. He would have been paid about $15 for Pepper and perhaps $300 for the entire truckload of animals.

The troopers gave Fay Brisk the news first, and she telephoned over to Montefiore that night. The switchboard operators told her no one was working in the animal quarters to answer her questions. Years later, Brisk would claim to have heard the jangling of dog tags at the other end of the line when she finally got through the next morning. Yes, someone at the hospital told her, the two Dalmatians did come in the previous week, but no, the older one was no longer there. On Friday, while Julia Lakavage was talking to the state troopers in Ulster County, her dog Pepper was splayed out on an operating table in a large building on Gun Hill Road in the Bronx. Medical researchers had tried to implant her with an experimental cardiac pacemaker, but the procedure went awry, and she died. The dog's body had already been cremated.

A hospital spokesman explained later that the order had gone out for six male Dalmatians, to be paid for by weight. The dealer had brought in two females instead.

Pepper's journey in the summer of 1965 helped start a national media sensation and a broad panic over the theft of pets for biomedical research. Her death on an operating table in the Bronx would help animal welfare advocates break a long-standing stalemate in Congress and push through the most significant animal-protection bill in American history. At the same time, she became a martyr to the cardiology revolution at a crucial moment in its development. Pepper also represents a turning point in science, from an earlier age when animals for experiment would be plucked from the road or the river, to a new era of standardized, mass-produced organisms that can be shipped right to the laboratory door. In a five-part seriesto be published over the course of this week, Slate will explore her legacy.

Man Cuts Dog

Here's one way to give a dog heart block: Anesthetize it, flip it over, and make an incision along the midline of its chest. Crack open the sternum and pull apart the bone and muscle. It's best to use a dog of medium size, with short hair and a long torso—like a Dalmatian. You won't be able to accomplish very much while the dog's heart is full of blood, so tie off the venae cavae with a tourniquet to block the flow into the right atrium. Remember to move quickly, as the dog can endure only a few minutes in this predicament. (You can buy some extra time by presoaking the animal in a basin of ice water.) Disrupt the heart's conduction mechanism by sewing a single, black silk suture between the tricuspid valve—which separates the right atrium from the right ventricle—and the coronary sinus. Now untie the tourniquet to restore the flow of blood, and you're done. If all goes well, the dog will have lost the ability to pace its own heart.

Every year, 200,000 Americans, and more than 500,000 people worldwide, receive a permanent cardiac pacemaker as a treatment for heart block, bradycardia, or another heart-rhythm disorder. The ubiquity of the pacemaker has a lot to do with the elegance of the procedure now used to implant it: The whole operation takes just an hour or two, it can be performed under local anesthetic, and patients are sent home the next morning. The safe and simple technique—in which doctors make a small incision near the collarbone, open a vein, and slide the pacing leads directly into the heart—was invented more than 50 years ago by Seymour Furman, a young resident at Montefiore Hospital who was spending his afternoons in the dog lab.

Early versions of the pacemaker were crude devices that attached to the external surface of the heart or the front of the patient's chest. A Boston physician named Paul Zoll installed one of the first modern devices in 1952. He wired up a pair of hypodermic needles and plunged them directly into a patient's skin. The pulse generator was a large, external box plugged into the wall. In 1957, an open-heart surgeon at the University of Minnesota started attaching the pacemaker leads directly to the cardiac muscle. This allowed the device to work at a much lower voltage—jolts from the earlier machine had sometimes blistered the patients' skin—but the electrodes were unstable, and it took major surgery to implant them.

Seymour Furman's great insight was to combine the new field of cardiac pacing with a medical procedure that had only recently become mainstream, cardiac catheterization, in which a thin tube is inserted into a blood vessel and advanced into the heart for diagnostic testing. The cardiac catheter had earned its inventers a Nobel Prize in 1956, and one of its early practitioners—Doris Escher—was Furman's mentor at Montefiore. With her guidance, he hoped to pass an electrode through the venous system to the right atrium, where he could pace the heart with more stability and less current than ever before. This would also eliminate the need for chest-cracking, open-heart surgery.

In the fall of 1957, Furman set to figuring out the details of his new procedure in the dog lab. The canine anatomy turned out to be perfect for the experiment: The dog's external jugular vein was large and easily accessible, and provided the catheter with a straight shot into the right ventricle. But before Furman could test the dogs with his new catheter leads, he'd have to open their hearts and induce an artificial block. That procedure proved to be dangerous: Of the 16 dogs assigned to Furman, only four survived.

Bill Miller arrived with his truck at Montefiore Hospital on Thursday, July 1. He'd spent several days carting two goats and 18 dogs across Pennsylvania and New Jersey, and had already sold most of the live cargo to medical centers in Manhattan. He unloaded the remaining animals that afternoon in the Bronx and set off for home.

One of the animals carted into the clinic that day would later be identified as Pepper, the adult, female Dalmatian who had recently disappeared from the Lakavage family's 82-acre farm near Slatington, Pa. While her former owners searched for her in vain, it's likely that Pepper was being stowed in a kennel on the roof of the hospital. It's also likely that her vocal cords were severed when she arrived, leaving her unable to bark and howl in her final hours.

Pepper spent just one night in the Montefiore kennels. Sometime on July 2, she was brought down to the dog lab, anesthetized, and prepped for surgery. A hospital spokesman later told the newspapers that she'd been scheduled to receive an experimental pacemaker.

By the summer of 1965, Seymour Furman had already worked out the basics of transvenous pacing. His technique enjoyed a significant following overseas, and the American medical device company Medtronic had just introduced its first commercial pacemaker with catheter leads. But there were plenty of problems still to be solved. Batteries died, pulse generators would fail, and patients had to make frequent return visits for follow-up surgeries. That year, the Atomic Energy Commission would start work on a durable, nuclear-powered pacemaker. (The first of these was implanted in a dog in 1969.) When Pepper arrived at Montefiore, Furman was hard at work developing his own, more permanent device, and he needed animals for testing.

On that Friday, Pepper's chest would have been opened like the other dogs, her sternum separated, and her venae cavae tied off to empty her heart of blood. It's not clear when or how the procedure went wrong. Perhaps the surgeons couldn't finish the operation in time to restore her circulation. Or maybe the induced heart block was too severe. Whatever happened, the experiment was a failure: Pepper died on the table.

The loss of a single Dalmatian meant little to the pacemaker program at Montefiore. The new prototypes would be tested on another dog, and another, and many more; Furman's research yielded plenty of discoveries in the years that followed. (To name just one: In 1967, he devised a way to check the function of an implanted device automatically over the telephone.)

Not even the doctors who were performing these experiments understood just how important the new inventions would soon become. Heart disease was already America's leading cause of death in 1965, as it had been since about 1930. But few cardiologists at the time had ever seen a case of heart block—most of its victims were elderly people with modest access to medical care, and they were dying before anyone could make a diagnosis.

That all began to change with the invention of Medicare. On July 9, less than a week after Pepper's death, the Senate voted to make health insurance universal for elderly Americans. Nineteen million patients enrolled in the program the following year, and it soon became obvious how many adults were suffering from slow heartbeats in their old age. Now, for the first time, there was enough money to treat them all.

The particulars of Pepper's death scarcely mattered to the revolution in cardiology. But her final moments on the operating table do carry their own historical resonance: Medical science as we know it today—constructed on a framework of experimentation, observation, and reason—had begun in much the same way a few centuries before, with a dog laid on its back, its breast cut open, and its heart snipped in two.

What might easily be called the founding experiments of modern medicine were conducted in the first decades of the 17th century, by English physician William Harvey. His crucial discovery that blood circulates in a closed system began with a series of gory demonstrations on the bodies of living animals. For one, he would expose the beating heart of a dog, horse, or other creature and puncture its left ventricle. The geyser of blood that erupted with each contraction suggested that the motion present in the arteries and veins wasn't mere sloshing about, as had been the theory, but rather the result of a "forceful systole" of the heart.

Those skeptical of Harvey's conclusions opened the bodies of living dogs to see for themselves, and according to historian and philosopher of science Rom Harré, the dog soon became a standard instrument for the study of circulation. By the mid-1660s, Christopher Wren had devised a method for the intravenous injection of chemicals—opium and Spanish wine, to start with—into the bloodstream of a dog, and Richard Lower had performed the first successful blood transfusion by using a chain of quills to connect the artery of one dog to the jugular vein of another.

Laika the space dog

The dog remained a vital tool in biomedical research for more than 300 years and was the vehicle for a remarkable run of medical breakthroughs. Ernest Starling's research on dogs led him to declare the existence of "hormones" in 1905. In 1921, Canadians Frederick Banting and Charles Best discovered insulin as a treatment for their colony of dogs with surgery-induced diabetes. In 1923, George Whipple used a Dalmatian-English bulldog cross to create a model of pernicious anemia, then cure the disease with supplements of liver. * And shortly before Pepper's death, a stray mutt plucked from the streets in Moscow became the first animal to be launched into orbit. Though that dog died from stress and overheating only a few hours into the mission, the feasibility of human spaceflight was reported around the world.

By the 1960s, Furman and his colleagues at Montefiore Hospital were using a few hundred dogs for research every year, while larger institutions went through as many as 9,000. Rep. Joseph Resnick, the upstate lawmaker who attempted to intervene on behalf of the Lakavages on the very day that Pepper was killed, would later assert to the newspapers (and his fellow members of Congress) that the annual number of dogs used in federally funded research had reached 1.75 million.

But the dog-napping of Pepper marked the beginning of the end of canine experimentation. Outrage over her demise, and the theft and killings of other family pets, would soon turn public opinion—and federal law—against the use of dogs in biomedical research. Meanwhile, the rapid growth of American science after World War II had already created a new industry in purpose-bred, standardized lab animals—and the thriving trade in stray mutts and stolen pets would soon be replaced by an assembly line of laboratory flies, rats, and mice. Pepper's death in the summer of 1965 signaled the end of an era.

Pepper Goes to Washington

Rep. Joseph Resnick planned to take Pepper's story to the Capitol even before anyone knew she was dead. The cigar-chomping congressman had been recruited to Pepper's cause on Friday, July 2, 1965, when a Pennsylvania family, the Lakavages, arrived in his upstate New York district in search of their missing Dalmatian. A local dealer had refused to let the family search his farm, and Resnick's appeals—to the dealer, the state troopers, and even the FBI—had come to nothing.

It soon emerged that the stolen pet never made it upstate. Pepper had been sold instead to a research hospital in the Bronx and her chest cut open in a botched test of a new cardiac pacemaker. Resnick commended Julia Lakavage, who drove 130 miles with her daughters and grandson in an effort to find Pepper, for "following through" and promised that he would take up their cause as "dog's best friend" in Washington.

Seven days after Pepper's death, Resnick introduced a dog-napping bill on the House floor. He wanted government licensing for the dealers and laboratories that traded in dogs and cats, and proposed that the theft of these animals be made a federal offense. For Resnick's colleagues in the House, the bill, born in a moment of outrage on the eve of the holiday weekend, must have seemed almost grotesque in its insignificance. On the very day it was introduced, they approved the Voting Rights Act, while the Senate agreed to add Medicare to the Social Security program. Yet little H.R. 9743—Pepper's law—would elicit more public engagement in the months that followed than either of these watershed measures. Resnick's bill broke a grueling stalemate over animal-welfare legislation and broke open a dispute that had lingered for 20 years between humanitarian activists and the emergent biomedical industry.

On Aug. 24, 1966, the president signed a more ambitious version of the proposal into law. But that was just the beginning. What began as a measure to prevent pet theft would soon become the most comprehensive animal-welfare legislation in U.S. history.

Ruff may have been a stray, or he may have been stolen; in any case, the article that accompanied his photograph in the New York Times hardly dwelled upon his provenance—the animal was identified only as "a friendly dog of uncertain ancestry" who had somehow ended up in the hands of the brilliant, Brooklyn-based heart surgeon, Adrian Kantrowitz. In 1958, Kantrowitz had dissected out the left half of Ruff's diaphragm, along with its major nerves and blood vessels, and wrapped the whole assemblage around his aorta. This "booster heart" could be stimulated to rhythmic contractions by a set of implanted, radio-controlled electrodes. At the time of his publicity photo, Ruff had survived for 18 months after the operation; now he was being honored for his efforts with a silver collar and official designation as the "Research Dog Hero Award" winner for 1959.

The silver collar, sometimes called the "Nobel Prize of dogdom," had been concocted in 1946 by the National Society for Medical Research, as part of a broad effort to defend the practice of animal experimentation from its most vocal critics. Those critics—the so-called "anti-vivisectionists"—had a powerful ally in William Randolph Hearst, who used his network of newspapers to editorialize against sadistic "dog torturers." Scientists believed it would take a major publicity campaign to overcome Hearst's hostile media empire, and the silver collar was one of their tactics.

Concern over animal welfare surged in the years after World War II, as the practice of biomedical research moved out of the private labs and become a massive public enterprise. The National Institutes of Health were consolidated in 1944 under the Public Health Service Act, and over the two decades that followed—running up until the time that Pepper was stolen in Pennsylvania—its budget rose more than 30,000 percent, from $2.8 million in 1945 to almost $1 billion in 1965.

That money was feeding a biomedical research establishment with an insatiable need for live animal subjects. To fill the empty cages in Bethesda, Md., and elsewhere, the NSMR lobbied for the enactment of "pound seizure" laws, allowing the forcible appropriation for research of any unclaimed strays that would otherwise be put to death. The first pound seizure laws were passed by the Minnesota Legislature in 1948, and many more followed. New York's Hatch-Metcalf Act allowed the seizure of cats and dogs not only from municipal pounds but from any private shelters holding government contracts.

These government incursions—and the rapid growth of the NIH—inflamed both animal-welfare activists and right-wing radicals. The two groups shared a deep suspicion of modern science and the growing power of technocrats in Washington. William Randolph Hearst straddled whatever line might have separated them, speaking out against animal research and warning his readers against New Deal bureaucracy and liberal academia. The anti-vivisection movement at large had at least incidental sympathies during this postwar era, with the reactionary (and sometimes anti-Semitic) campaigns against fluoridation and the polio vaccine.

(The same right-wing rhetoric was also marshaled against the animal activists, who were attacked for being Communists or worse—Hitler and Mussolini were well-known vegetarians. A 1950 editorial from the Los Angeles Times growled that "the fanatics who oppose animal experimentation for sentimental reasons are being joined, and in some part led, by Communists and Communist sympathizers interested in sabotaging national defense.")

Christine Stevens at the Humane Society of Washtenaw County, Mich., in the 1950s

Meanwhile, the burgeoning animal rights community gave rise to a Python-esque set of rival factions. The pound-seizure bills divided the moderates of the American Society for the Prevention of Cruelty to Animals, who were content to let scientists use unwanted strays in place of purpose-bred animals, from the hard-liners in the National Anti-Vivisection Society, who were opposed to any animal research whatsoever. In 1951, D.C. activist Christine Stevens formed the Animal Welfare Institute with the express purpose of charting a "middle course" on animal research; she supported the use of pound animals but only for acute experiments under full anesthesia. Three years later, a dispute over whether and how to address pound seizure broke up the American Humane Association, with a dissident faction going on to become the Humane Society of the United States. That group was itself divided in 1959, when one founder departed to form the Catholic Society for Animal Welfare.

The National Society for Medical Research continued its lobbying efforts and red-baiting publicity campaigns throughout the 1950s, but despite its divisions the animal-welfare movement—like other progressive causes of the time—was growing in strength. By the time the society gave Ruff its silver collar in New York, Christine Stevens and the rest of the dog lovers were ready to make their push in Congress.

The beagles in the basement were kept there by the hundreds, locked in cages 2.5 feet wide and 3 feet long. In November 1959, just a month before Ruff's photo shoot, nationally syndicated journalist Ann Cottrell Free published her first account of the animal quarters at the South Building of the Department of Agriculture, where government scientists tested food dyes on animals that were deprived of exercise for years at a time. "Hundreds of dogs flung themselves against the bars of their cages, piled tier on tier," she wrote. "They were barking, screaming, whining, mute—and drooped their heads in the dark corners. Others circled ceaselessly in their cages."

The revelation that dogs—adorable beagles!—were being so cruelly mistreated just a 20-minute stroll down Independence Avenue from the Capitol Building had an immediate impact. Free distributed her articles to key members of the Senate appropriations committee, and Congress soon delivered $100,000 for new animal quarters in Beltsville, Md. During the same congressional session, Sen. John Cooper introduced the first comprehensive federal bill to protect laboratory animals.

Sen. Joseph Clark of Pennsylvania

Prohibitions against cruelty to animals had been on the books of every state in the union (plus Alaska and Hawaii) since the start of World War I, but most of these were based on a New York statute from 1867, drafted by the gentleman activist and founder of the ASPCA, Henry Bergh. That law, and many of those that followed, made a point of excluding animals subject to "properly conducted scientific experiments or investigations."

Cooper's 1960 bill would have established animal-care standards for any facility receiving federal research grants. Authored by Abe Fortas (a few years before he was named to the Supreme Court), the proposal drew heavily from the United Kingdom's Cruelty to Animals Act of 1876, which required that all users of laboratory animals register with the government and make annual reports of their research. An additional certification was required for anyone who wanted to perform painful experiments and yet another for painful work with dogs or cats.

Those terms may seem rather modest by today's standards, but in 1960 they set off a long debate over the extent to which scientific progress had been retarded by the laws in Britain. Indignant testimonials from British scientists were read before Congress, and the results of British surveys were published in the New York Times. American researchers attributed their extraordinary breakthroughs in open-heart and thoracic surgery to liberal policies on the use of dogs, and the Brits countered that they had, in fact, received more Nobel Prizes for Physiology or Medicine than the Yanks, per capita.

In any case, Cooper's bill—which had the support of Christine Stevens and the Animal Welfare Institute—was ridiculed by hard-core anti-vivisectionists, who lobbied against it as "a snare, a delusion and a fraud." A more restrictive version favored by the Humane Society soon followed, along with a scaled-down bid from the American Humane Association and an NSMR-backed pitch for the upgrade of government-funded animal facilities. Laboratory-animal bills of all types would be introduced by the dozens over the next five years; newspaper endorsements piled up. While angry debates raged among the animal rights activists, not a single proposal came close to being passed.

Congress had little interest, at first, in the fact that someone's dog had perished in a medical experiment. It was Pepper's 10-day ordeal in the hands of scurrilous dog dealers that had inflamed Rep. Joseph Resnick and her journey across interstate highways that inspired his "dog-napping" bill in the summer of 1965. At hearings in September, he dispelled any notion that his proposal was intended to aid the anti-vivisectionists: "This bill is concerned entirely with the theft of dogs and cats," he said, "and, to a somewhat lesser degree, the indescribably filthy conditions in which they are kept by the dealer."

Indeed, the law didn't seem to have much bearing on the issues that were most important to animal-welfare groups. It focused only on dogs and cats and gave enforcement authority to the Department of Agriculture, which had close ties to the livestock industry. Worse, it took no position on the actual practice of research—all regulation would stop at the laboratory door. For Christine Stevens and her fellow moderates, though, the pet-theft bill was a chance to move forward.

They knew Pepper's story would strike a chord with the American public. Dog ownership was on the rise through the 1960s—one study found it increased by more than one-third—and stolen purebreds had been the subject of the enormously popular 1961 Walt Disney feature, 101 Dalmatians. (Lady and the Tramp, with its own sad portrayal of canines in captivity, was reissued in 1962.)

In a matter of weeks, eight more dog-napping bills were brought to the floor of the House, and Joe Clark—whose office took the first call on Pepper's disappearance—introduced one in the Senate. By the following spring, Resnick's bill had spawned a total of 33 others.

Stories of pet theft multiplied just as rapidly in the newspapers. After tracing Pepper to Montefiore Hospital in July, activist Fay Brisk turned her attention to a purebred, black-and-white English setter that had vanished from a farm in Boyce, Va. That dog turned up at the NIH in Bethesda and was returned to its owner in August. A few months later, Brisk found a stolen Irish setter named Reds at a hospital in New York and sent him home to a family in suburban Philadelphia. Then there was Alvin, a black cocker from New Jersey, and Peanuts, a German shepherd from Falls Church, Va.

Life Magazine article from Feb. 4, 1966

The most significant contribution to the dog-napping panic arrived in February 1966, when Life magazine released an eight-page photo essay, "Concentration Camps for Dogs." (A cover line warned, "Your dog is in cruel danger.") Life photographer Stan Wayman had joined Humane Society investigators on a raid of a dog dealer's farm in Maryland, where animals were chained to wooden boxes and left out in the cold to feed on frozen entrails. Christine Stevens distributed a copy of the article to every member of Congress.

Lawmakers claimed to be getting more mail on the subject of dog-napping than they were on Vietnam: The Senate commerce committee received 20,000 letters over the 12-month period beginning with Pepper's death; the House agriculture committee counted 60,000. At the beginning of March 1966, the House held two days of hearings to sort through the growing stack of animal welfare bills. The Humane Society's Dec Hogan testified to the ugly details of the raid in Maryland: The dealer, he said, "showed us a beagle, blind in one eye and pus running from the other." According to the New York Times, the huge hearing room was crammed with spectators, and the crowd spilled out into the hallway.

Meanwhile, the medical establishment was in retreat. The NSMR abandoned its Research Dog Hero program in 1965, the same year that one of its two founders was charged with fraud by the FDA. In the face of the publicity surrounding Pepper and the Life photo spread, the research lobby changed tactics: Now it would try only to moderate whatever bill was coming down the pipe. Scientists had good reason to worry. By that point, Resnick's original proposal to prevent the theft of dogs and cats had been expanded to cover the treatment of all warm-blooded laboratory animals, stolen or not.

Lobbyists for the universities and hospitals succeeded, at first, in scaling back the bill's most ambitious provisions, but a last-minute push in the Senate restored some of what had been stripped away. When the final version of the Laboratory Animal Welfare Act was signed into law in August 1966, its guarantees of humane treatment extended both to the dealers' premises and to the research holding facilities where animals were kept before experiments. It now applied to every dog, cat, monkey, rabbit, hamster, and guinea pig in federally funded labs.

For the activists, though, Pepper's law was at best a foot in the door. The act protected the animals where they were housed, but it had no impact on their treatment inside the lab, where some of the most distressing cruelties were taking place. "This was the breakthrough and end of stalemate," said Free. "We decided, Well, we'll just have to go ahead and year after year, whenever we can, amend it and strengthen it, amend it and strengthen it."

That's just what they did.

Brown Dogs and Red Herrings

On a balmy June morning in 2007, a pair of Pennsylvania congressmen gathered their colleagues in the basement of the Rayburn House Office Building to show them a video. The lawmakers watched excerpts from a documentary that had aired on HBO the previous winter, about an unscrupulous dog dealer in Arkansas who was selling animals to laboratories. About 40 years after Pepper's story prompted the first federal dog-napping law, the wheels were in motion on another. Mike Doyle, D-Pa., introduced the film: "It's hard to believe that someone would steal people's pets and treat them this way."

Despite the film, the Pet Safety and Protection Act failed to pass in 2007, just as it has on a nearly annual basis for the last 13 years. Should it ever succeed, the law would ban the sale of any dogs and cats for research by "Class B" dealers—those who collect or buy their animals rather than breeding them themselves. (If such a designation had existed in 1965, it would have applied to the three men—Jack Clark, Russ Hutton, and Bill Miller—who handled Pepper during her 10-day journey to the dog lab.) That's not an unreasonable goal—as the HBO special showed, the Class B dealers are almost certainly engaging in some shady practices—but it hardly seems worth the sustained efforts of the nation's top animal welfare advocates. To put things in perspective, only about a dozen of these dealers remain in business, and they sold fewer than 3,000 dogs to research labs in 2008. Those dogs, stolen or not, represent just afew thousandths of 1 percent of all the animals used by American scientists.

It's not too long ago that dogs and cats mattered a great deal to the practice of biomedical research. Today they're barely relevant—a tiny, shrinking line item on an enormous ledger of death. Something like 100 million animals are killed in experiments every year in the United States, yet groups like the Humane Society of the United States and the Animal Welfare Institute continue to treat a handful of pet thefts as a keystone issue. How did a broad struggle for the ethical treatment of lab animals turn into a border skirmish over missing pets?

Dogs were already a favorite of scientists when live-animal experimentation became widespread in the mid-19th century. Bred for docility over many thousands of years, the dog evolved as an ideal animal for the lab, simple to feed and house and poke and slice. It was also easy enough to imagine man's best friend as a stand-in (and a physiological model) for people: What's true for Pepper must be true for us; her heart must beat like mine.

Potential test subjects were everywhere in the early days of vivisection. A fascinating paper by historian Bert Hansen describes how American cities of the Gilded Age were beset with stray and wild dogs. In 1885, the New York Herald guessed there were some 300,000 in Manhattan and another 150,000 in neighboring Brooklyn. The scourge invited open brutality: Police officers were empowered to shoot dogs in the midst of rabies panics, and captured strays were crammed into cages and drowned in the East River.

From the start, though, the use of dogs for violent laboratory experiments disturbed a bourgeois sensibility that associated them—or at least the purebreds—with family and the comforts of domestic life. (Many years later, Julia Lakavage would tell reporters that Pepper and her other dogs were "like family members … children that don't grow up.") That notion extended to the very upper reaches of society: Queen Victoria of England—whose menagerie of pets included Skye terriers Islay, Cairnach, and Dandie Dinmot; King Charles spaniel Dash; greyhound Nero; mastiff Hector; and many more—was well-known to be suspicious of the new science of animal experimentation. In 1875, the year before the passage of Britain's Cruelty to Animals Act, Victoria asked Joseph Lister to speak out against vivisection: "The Queen has been dreadfully shocked at the details of some of these practices," her secretary wrote, "and is most anxious to put a stop to them."

The court watches a reconstruction of William Bayliss's physiology lecture during the 1903 trial over the "Brown Dog Affair."

By the first decade of the 20th century, the plight of research dogs had become the principal cause for animal activists, who singled them out on account of their vulnerable nature—and the ease with which they could be used to elicit public support. In February 1903, a pair of Swedish animal lovers slipped into a medical demonstration at University College London and watched physiologist William Bayliss cut open the neck of a brown dog. In their published account of the episode, they claimed that the animal had suffered under improper anesthesia. Riots erupted after a monument was erected to the anonymous brown dog. (Tensions over the "brown dog affair" have been revived in England several times since.)

Scientists responded to the furor over experimental dogs with anger and derision. Historian Susan Lederer cites a 1910 screed by a New York physician who accused the anti-vivisectionists of suffering from a kind of "zoophilic psychosis": They "interest themselves not so much in experiments upon fishes, insects, pigeons, rats, mice, snakes, nor in cruelties to men, cattle, chickens, and sheep," he wrote. "Their interests are bent towards those useless animals which can be made the objects of fondling and which compared with other animals play a minor role in the great field of scientific experimentation."

Within a few years, the concern over experimental dogs crystallized into a fear that pets were being stolen and sold to research institutions. The specter of "dog-napping" became central to the activist rhetoric starting in the 1910s, says Lederer, and soon showed up in animal-welfare exhibitions and pamphlets with titles like Guard Your Dog. Meanwhile, the dog-theft meme percolated through the media—and not only in the newspapers of ardent anti-vivisectionist William Randolph Hearst. In the early 1920s, the New York Times offered regular coverage of a gang of "auto-pirates" who pilfered more than 150 animals from wealthy estates on Long Island. That story, and others like it, were summed up in a Times headline from February 1922: "Stealing Fine Dogs a Regular Industry … Most Intelligent of Their Kind, but Have Never Learned How Not To Be Stolen."

The epidemic of pet theft received intermittent coverage over the next few decades. With the re-emergence of the animal welfare movement in the 1960s—and the disappearance of Pepper in Pennsylvania—it became a national story.

At the turn of the century, animal activists organized their campaigns around research dogs and cats, but science was already moving in a new direction. Mendel's ideas had been rediscovered in 1900 and the term geneticscoined in 1906; the new science of heredity created a sudden need for organisms whose exact ancestry was known and controlled. Within a few years, the perception and practice of biomedical research had begun to diverge: While humane societies were worrying about missing pets, researchers were shifting to a new set of standardized, purpose-bred laboratory organisms—the rat, the mouse and the fruit fly.

The standardization of laboratory animals reflected the growing influence of industrial engineering in America. Under the new paradigm, research organisms could be seen as a sort of raw material for use in a knowledge assembly line. Just 10 or 20 years earlier, a physiologist might have conducted his experiments on a variety of species—frogs and rabbits, for example, or dogs, horses, and baboons—to show that a finding could be generalized across the whole of creation. Now, whatever could be demonstrated in a rat or a mouse was assumed to be true of a dog, a horse, or a human. The growth of statistical science also changed the nature of laboratory work: Now it was advantageous to increase your N by repeating an experiment as many times as you could on as many animals as were available.

Biomedical science became even more industrialized during the postwar period as government money flowed through the pumped-up National Institutes of Health. Grants officers realized that animals could be most efficiently distributed if they were churned out in large numbers at a few, centralized locations. Meanwhile, the organisms themselves had begun to be packaged as commercial products: In 1941, the breeders at the Jackson Laboratory in Maine received a patent on their line of "JAX Mice" research animals; a year later, the Wistar Institute in Philadelphia trademarked its own line of "WISTARATs."

Experimental dogs had been well-suited to the old-fashioned, artisanal mode of inquiry—William Harvey cutting open a heart, Christopher Wren pumping a vein full of wine, Richard Lower transfusing blood with a chain of quills. But as an instrument of modern science, they were starting to look obsolete. The economics of breeding dogs were one problem: In 1965, the year Pepper was taken, a dog could be raised and maintained in a research lab for about 70 cents per day. At that rate, though, it would cost more than $250 to produce a single, sexually mature animal. A stray with uncertain heritage could be had from a dealer for just $15, which explains why hospitals were buying dogs like Pepper to begin with.

That's not to say dogs didn't have their niche in biomedicine. Medical schools, in particular, made ample use of them for education and research in surgery and cardiology. And many of the landmark studies on anemia, diabetes, hemophilia, and cardiothoracic surgery used dogs. But by the time of Pepper's death, there was already a move toward replacing canines on the operating table with a brand-new model organism—the miniature pig. The hairless and docile Yucatan mini-pig had been introduced to the United States in 1960, and the University of Missouri opened a dedicated miniature swine production facility in 1965.

Like dogs, miniature pigs were big enough to operate on but not so big that they couldn't be housed and handled. Porcine skin turned out to be so similar to our own that it could be used as a temporary patch for burn patients and a vehicle for the study of melanoma. Mini-pigs were also excellent subjects for the study of cardiovascular fitness, atherosclerosis, obesity, and diabetes.

A total of 260,000 dogs were used by U.S. labs in 1967, the year that Pepper's dog-napping law took effect. Over the next four decades, that number would drop by almost 75 percent. Surely some of that decline has come in response to continuing pressure from animal-welfare activists. (Research on miniature pigs isn't as likely to draw angry protests.) More significant, though, was the fact that science itself had changed.

The Laboratory Animal Welfare Act passed in 1966 gave some protection to a small number of species in limited settings. But the animal rights activists, emboldened by success, were soon able to broaden its scope. The first major amendments arrived in 1970; from then on, the law would be known simply as the "Animal Welfare Act," and its reach extended to circuses, zoos, shows, and wholesale pet dealers. The laboratories, too, had new responsibilities: Where the 1966 version had applied only to research holding facilities—with cage-size and feeding requirements, for example—now the experiments themselves were subject to humane standards, including pain management whenever possible. But what might have been the most significant change to Pepper's law was a broadening of the very definition of the word animal. Instead of protecting only the most lovable critters—dogs, cats, nonhuman primates, rabbits, hamsters, and guinea pigs—the new law could be taken to apply to every other warm-blooded animal used in the lab.

That dramatic mandate was handed over to Dale Schwindaman, a federal veterinarian who had been summoned to Washington four years earlier to help draft the original regulations related to Pepper's law. It hadn't been easy for the Department of Agriculture to enforce the original act; now Schwindaman had to figure out how to address a raft of new responsibilities.

The numbers were grim. A laboratory-animal survey conducted by the National Academies of Science found that the original covered species—the cute animals—made up just 7 percent of the total used in U.S. labs. In addition to the 260,000 dogs, there were 100,000 cats and 800,000 hamsters. But there were 30 million rats and mice. "The job was too big," Schwindaman says. Full coverage of warm-blooded species would have given the USDA the obligation to supervise every last junior college that used rodents or chick embryos for teaching. "The math just did not allow it. … We couldn't use the National Guard to make all of these inspections. We didn't have the force."

With Schwindaman's help, the USDA put in place in 1972 a special exemption for rats, mice, and birds, allowing scientists to treat them however they saw fit—in cages of any size, in experiments with any degree of pain and suffering. That exemption remains in force, despite Schwindaman's later attempts to overturn it. To this day, 95 percent of the animals used in research labs receive no federal protection whatsoever under the Animal Welfare Act.

In the fall of 2001, an undercover animal activist took a job cleaning rat and mouse cages on the Chapel Hill campus of the University of North Carolina. Over the next six months, she would collect more than 40 hours of footage on behalf of People for the Ethical Treatment of Animals with a camera hidden under her lab coat. The video showed researchers marking newborn mice by amputating their toes and cutting the brains from baby rats without anesthesia. Rodents were trampled to death in overcrowded cages, left to die in garbage bins, or allowed to suffer with swollen tumors and open sores.

"That was such an enormous disappointment," says PETA's director of laboratory investigations, Kathy Guillermo. The story of a single dog had once been enough to pass the country's most important animal-welfare law, but evidence of repeated rodent abuse in a government-funded lab barely made the news. "It's because it's mice and rats," Guillermo says. How do you protect an animal that most Americans would be happy to kill themselves with glue traps, even, or poison?

1937 Life Magazine cover story about C.C. Little's cancer research mice

The rodents' PR problem helps explain how they came to infest science and medicine in the first place. C.C. Little, the inventor of the modern lab mouse and founder of the Jackson Laboratory, had long used "the age old enmity of woman and the Muridae" as a sales pitch for his model organism. Writing in American Naturalist in 1939, he noted that "it has been difficult to keep at fever heat a sufficient level of sympathy for the rodent similar to that which the dog or cat engenders." Indeed, when controversy erupted over Pepper's death in 1965, Little's company was quietly supplying physiologists with close to 1 million mice every year. (Today, the sales of rats and mice dominate a $1.4 billion global market in laboratory animals.)

For 100 years or more, scientists and activists had traded blows over the ethics and practice of research on dogs and cats. Through all that back-and-forth, lab rodents were always left just across the moral frontier of live-animal experimentation—close enough to humans to remain a meaningful source of knowledge but not so close that we couldn't slaughter them in droves. Yet it's not obvious—to those who might consider the question—that the welfare of a rat or mouse is any less important than that of a dog. Recent research suggests that the health of mice improves when they're given cage toys, running wheels, and crawl tubes to play with. Rats can learn to respond to a name and recognize individual people. We might quarrel over the inner lives of honeybees or river trout, but is the suffering of our fellow mammals really in question?

The animal-welfare groups have failed in their most ambitious efforts to protect laboratory rodents. "We did and do strongly support the inclusion of rats and mice," says Cathy Liss, current president of the Animal Welfare Institute. "But the question is how can we properly address that? At this juncture, it's premature to go forward and rally support." With rodents off the table, though, it's not clear what's left for the activists to do.

Me and My Monkey

My research monkey had a pink face, dark eyes, sandy fur, and a 2-inch titanium rod screwed into the top of his skull. His name was Clayton.

It's customary to name research macaques in alphabetical order according to when they arrived at the lab. Clayton showed up after Axel and Bongo and ahead of Duper, Einstein, and Freud—but whatever institutional seniority he had meant little in the monkey room. Clayton, a juvenile, was skittish and shy, submissive as a rule, and generally afraid to leave his cage. When I'd finally manage to coax him out, he would leap straight into the "monkey chair," preferring enclosure in a small, plastic box to the thought of ambling across the laboratory floor.

Though he hardly needed it, Clayton was leashed even for these short trips from cage to chair. I'd hook a chain to his collar and slide it through a loop at the end of a 3-foot pole so he couldn't get close enough to bite or scratch. Macaques can harbor the deadly herpes B virus, and it's generally forbidden to approach one that's unrestrained and un-anaesthetized. Though Clayton and I spent hours together every day, I never so much as touched his fur during an experimental session. If he came to recognize me—and I believe he did—it was despite the surgical mask, goggles, hair net, and other safety accoutrements of any visit to the monkey room.

The monkey chair wasn't much bigger than the animals themselves, and Clayton's head poked out through sliding panels at the top. I'd roll him in front of a computer monitor and fasten his protruding metal post to an external frame. With his skull fixed in place, only his eyes could move to follow the targets that zipped across the screen. (By tracking the direction of Clayton's gaze, I'd hoped to learn something about how smooth pursuit eye movements are controlled in the brain.) His eyes would follow me, though, as I loaded up the software and filled his juice dispenser; sometimes I'd place a jelly bean or a raisin delicately on the edge of his mouth, which he'd gobble up before flashing his gums in the deferential gesture of silent bared teeth. I talked to Clayton, too, trying to keep him entertained. But every once in a while he'd show his impatience with a gesture that was disturbingly human: I remember the day he crossed his legs on the shelf of the chair and started strumming his fingernails against the wall.

The one time I held Clayton in my arms, he was asleep and swaddled in a blanket. He'd just undergone a minor surgery, probably to repair a broken eye coil. (Most of the monkeys in the lab had a thin wire implanted under one eyelid that could be used to track their eye movements.) As a junior graduate student, I wasn't allowed to do more than observe the procedure, but when it was done, one of the postdocs lifted Clayton off the table and beckoned me over. I was to carry him back to the monkey room and deposit him gently into a cage before the anesthesia wore off.

For the first time, I felt the shape of his body—the outline of his little shoulders and spindly legs. For weeks we'd interacted across bars and through thick plastic; now I had him cradled him against my chest, his eyes closed and his head tucked into the crook of my arm. He was about the size and weight of a newborn baby; with the blanket wrapped around him, only his pink face was showing, and his eyelids fluttered as I carried him down the hall.

I rocked Clayton back and forth as we made our way to the monkey room. The rest of the animals were stored in interlocking cages, stacked two high on either side; a television in the corner was showing The Lion King on an endless loop. Axel, Bongo, and the other macaques watched as I squatted next to an open enclosure, with the bundle now nestled in my lap. I pulled one end of the blanket and began slowly to unwrap it. First once around and then again—the monkey was stirring now, his head rolling from side to side—and then the blanket was open, laid across my thighs, and there was Clayton's naked body in full view. His chest wasn't soft and pink like a baby's but tan and rugged. He had a tattoo across his abdomen of letters and numbers like the ones painted on houses in the aftermath of Katrina. And further down, nestled amid the light fur of his thighs, lay his penis—hardly the smooth, unformed genitalia of a baby but something like that of a fully grown man, shrunken down to the size of a crayon and adorned with a pair of swollen, red testicles.

A quiver went through Clayton's whole body as I took in this sight, and then a stream of liquid erupted from his groin, gradually building like a fountain that's just been switched on. An arc of urine splashed against my shoulder—and suddenly the monkey room was bedlam. Macaques began to throw themselves against the walls in a cacophony of shrieks and crashes. One animal in the upper tier started doing back flips; his neighbor stepped toward the front of his cage, turned in my direction, and started urinating, too.

I placed Clayton's small body into his cage, locked the door, and retreated to the safety of the hallway. The postdoc who had assigned me this task smiled as I peeled off my wet lab gown and T-shirt. "Don't worry," he said, as if it happened all the time.

Just as zookeepers rarely share the names of their animals with the public, so are laboratory monkeys left anonymous in the science literature. If I'd had the opportunity to publish the results of my work with Clayton, we would have called him Monkey C, in accordance with journal etiquette; other mammals, like mice, rats, and kittens, are almost never identified, even in code.

That hasn't always been the case. Ivan Pavlov called his surgical dogs by name in published lectures. Among his most successful subjects was a collie-setter mutt named Druzhok, "Little Friend." The anti-vivisectionist movement was much stronger in the United States than it was in Russia, though, and American physiologists were soon hiding the more sentimental details of their work from the public. In 1914, the chair of the Council on the Defense of Medical Research, Walter Cannon, warned journal editors to excise from their manuscripts any "expressions which are likely to be misunderstood" or turned against them by animal activists. Historian Susan Lederer has traced the expansion of this policy over 25 years at the nation's top biomedical research journal. Starting in the 1920s, she writes, a slew of technical jargon was systematically inserted into the pages of the Journal of Experimental Medicine. The word starving was replaced by fasting, bleeding by hemorrhaging, poison by toxicant; full-body photographs of lab animals were removed, and the pronoun it was subbed in for any use of he or she to describe them. Authors who referred to their animals by given names were instructed to use a string of letters and numbers instead.

That doublespeak (by now having become a matter of habit) obscures some of the incidental cruelties of animal research. But it hides just as well the attention and care that are essential to working in the lab. An experimental macaque costs about $8,000 and may require months or years of training before it can start producing useful data. That is to say, its continued health is of extraordinary value both to the professor who paid for it and to the graduate student whose dreams of a thesis depend on its well-being. It was my job to nurture Clayton so he would perform in my experiments as best he could. Given the constraints of the lab—a cage, a chair, a metal head post—I wanted him to be as happy as a monkey could be.

Outright negligence might have affected the quality of my data, as an animal in distress is likely to deliver skewed results. That idea, so obvious in retrospect, dawned on physiologists only near the turn of the 20th century, according to historian Otniel Dror. Researchers began to notice how fear or anxiety could be expressed as physiological phenomena—changes in blood sugar, for example, or digestive function. A fearful rabbit might "blush," wrote one scientist, and yield false measurements of blood pressure. While journal editors of the 1920s worked to strip emotional phrases from the scientific literature, scientists learned how to control emotion in the lab. Walter Cannon, whose letter in 1914 inaugurated the era of science-journal jargon, remarked that he could alter the gastric motility of a cat by "reassuringly" stroking her fur.

I've also experimented on cats—kittens, really—by probing their exposed brains with an electrode to see where tiny shocks might palpitate their feet. (We were studying neuroplasticity and how behavioral training affected the development of the motor map.) I spent time with the animals every day, teaching them to grab morsels of meat from a plastic container with their little paws. Like Walter Cannon, I stroked their bellies, too, and scratched under their chins. But there's no mention of those affections in the published results of the study. (Kittens "were trained to reach through the aperture to grasp the beef from a narrow cylindrical food well (3.2 cm inside diameter; 5 cm deep) using their preferred limb only," we wrote.) Nor did we mention that the animals—some as young as 3 months old—were euthanized at the end of each "intracortical microstimulation" experiment.

It's easy to see why we used this furtive language. Any sentimentality over the cats would have suggested a lack of scientific rigor, and a frank description of the killings would only invite anger from animal rights groups—and alienate the taxpayers who paid for the study (and my graduate student stipend). But it seems to me the pressure to keep the laboratory door shut comes from both sides. The public acceptance of animal research, and the biomedical breakthroughs it engenders, has always come with the understanding that no one will divulge too many of the gory details—we put up with animal sacrifice only so long as we don't have to think about it.

On Sept. 11, 1981, police officers in Montgomery County raided the two-story Institute for Biological Research in Silver Spring, Md., and found there a gruesome, filthy holding room for experimental macaques "who were in such physical and mental stress that they appeared to have bitten off their fingers and arms, or whose cages were locked together so that they injured each other." With the help of a young animal rights activist named Alex Pacheco, the officers seized 17 of the animals, and the lab's director, Edward Taub, was charged under state law with more than a dozen counts of animal cruelty.

Photograph taken by Alex Pacheco at the Institute for Biological Research in Silver Spring, Md.

Taub's trial began in October 1981, and as happens in nearly every case of alleged laboratory animal abuse, the ugliness of invasive research became a defense in itself. Should the condition of Taub's monkeys have been taken as evidence of abuse on its own terms or in the context of how research monkeys were treated everywhere else? Expert witnesses debated every detail of the case along these lines, from the question of how filthy a monkey lab might reasonably become to whether it made sense to bandage the wound of a deafferented animal. Taub was found guilty on six counts, but five of them were overturned in a second trial the following year; he was acquitted of the sixth in 1983.

The plight of the monkeys had in the mean time generated enormous publicity for Pacheco and his fledgling advocacy group, People for the Ethical Treatment of Animals. The photographs he'd taken in Taub's lab became the iconic images of an invigorated anti-vivisectionist movement—in particular, a shot of a macaque with its hands and feet taped to a metal frame and its arms stretched Christ-like. (At his trial, Taub accused PETA of staging some photos.) In 1984, PETA scored another publicity coup, releasing video footage stolen from the University of Pennsylvania by the Animal Liberation Front. That tape showed researchers at a head injury clinic joking around as they performed violent whiplash experiments on helmeted baboons. The uproar over the abuse in Silver Spring and Philadelphia pushed lawmakers to strengthen federal protections for laboratory animals. Like Pepper 20 years earlier, PETA's monkeys and baboons helped break a stalemate in Washington between animal welfare groups and the research establishment.

For years, a bioethicist named Bernie Rollin had been arguing that the Animal Welfare Act needed to be rebuilt with a new philosophy. In Rollin's view, the existing regulations had done little to make scientists aware of their animals' suffering. He'd testified in Congress that physiologists had not even bothered to study animal pain in a systematic way, since its existence could not readily be tested or verified in the lab. Researchers might use paralytic agents (sometimes called "chemical restraints") to prevent an animal from thrashing around during an experiment, he said, but they often neglected the use of painkillers altogether. This ideology even extended to human infants, whose subjective experience was similarly mysterious. Doctors sometimes assumed that babies were insensitive to pain and, up through the early 1980s, deprived them of analgesia during surgery.

With PETA's help, Rollin and the animal welfare groups were finally able to win their case—and the passage of a series of amendments to the Animal Welfare Act in 1985 under the stewardship of Bob Dole. The new law required that all covered animals be given painkillers before and after surgery and that no animal be used in more than one "major operative experiment." It also mandated the creation of an institutional committee (including at least one veterinarian) wherever lab animals were used. The self-policing committees were to review experimental protocols, inspect research facilities, and evaluate whether sufficient effort had been made to reduce animal suffering.

Rollin wanted more than bureaucratic airlocks, though. He'd tried to imbue the law with a new philosophy. The amendments he helped to write introduced the idea of "performance standards" for laboratory animal care, as opposed to the "engineering standards" of old. Where the USDA's Dale Schwindaman once struggled to determine the minimum cage dimensions for dogs, cats, and hamsters—"to play God to the animals," in the words of his boss—now there was a movement to abandon recipes and regulations in favor of more ambiguous endpoints. Government inspectors would spend less time unfurling their tape measures and more time adjudicating the spirit of animal welfare: Are the laboratory dogs getting enough exercise? Are the monkeys in a state of "psychological well-being?"

That distinction, between engineering standards and performance standards, has become a source of contentious debate among animal protectionists and research advocates. (Performance standards seem poised to become even further established in an upcoming revision of the official NIH Guide for the Care and Use of Laboratory Animals.) The institutions argue that more flexible definitions are better for the animals, since they allow for quicker improvements to laboratory practice. (Under performance standards, for example, monkeys might be housed in pairs or they might not, depending on their personalities and predilection for fighting.) Welfare advocates argue that wishy-washy requirements leave too much power in the hands of on-site experts, who draw their salaries from the institutions they oversee. Christine Stevens, the mother of the original Animal Welfare Act and the woman who first brought Pepper's story to Washington in 1965, worried that performance standards "gave it all back to the researchers and said, 'Here, do what you want.' "

"I'm not a 'law' type of guy," Rollin says now. "I'm a Harley rider. I was the last guy to want to play cops-and-robbers with scientists." Instead of handing out a new set of rules for researchers to follow, he'd hoped to make them work out the ethical issues for themselves.

I returned to the monkey room one morning in March, in a yellow lab gown with paper booties over my sneakers. I'd e-mailed my former mentor two days before, to tell him I was writing about animal research for Slate and to find out what became of the project we'd started in his lab eight years ago. Had someone finished the experiment? Were the remains of monkey C buried in some academic journal with my data on the headstone? In a few hours, I had his reply: "Clayton is still around."

The primate quarters were arranged exactly as I remembered—two rows of metal boxes along the walls, two tiers on each side. A pair of adult monkeys idled near the front of their cages on the right, just inside the door: One looked haggard, with circles of dry, red skin around his eyes and his tongue lolling from the corner of his mouth; the other was more alert, eyeing me from the front of his cage with his hands folded across his belly. If there hadn't been labels the size of index cards on the front of their cages, I might not have recognized Duper and Clayton at all.

Their enclosures looked smaller than before—cramped, even—and for a moment I considered the possibility that the recession had taken its toll on the animals. Of course, it was that the animals had grown bigger: Clayton had doubled in size—the little monkey who once felt like an infant in my arms was now a slouching beast with round shoulders and thick legs. His catarrhine muzzle was more prominent than before, and there was a new mound of pink dental cement on the front of his cranium, topped by a small, plastic screw cap. Beneath it was a patch of his brain, exposed for recording electrodes. I found myself gazing dumbstruck at his queer, time-worn face.

If Clayton remembered me, it wasn't with fondness: He rose to all fours as I approached and grunted at me with his lips parted—an aggressive, open-mouth threat. There was little evidence of the adolescent who had cowered in the back of his cage eight years ago. As an adult, Clayton lingered near the bars, scowling. (I discovered later that he'd been separated from his old cage-mate Duper for fighting.)

But the constancies of his daily life were more striking than these other developments. In all the time I'd been gone, Clayton had lived in the same room, on the same feeding schedule, and with many of the same neighbors. Since we'd last seen each other, I'd moved across the country twice, quit graduate school, and become a journalist. Scientists had published more than 10,000 research papers using macaque models, and a team at the Baylor College of Medicine sequenced the entire genome of the rhesus monkey. For Clayton, though, nothing has changed. Every day or two, he's carted off to a room painted all in black, and his head is fixed in place by the post that still protrudes from his skull. He sits there as always, staring at targets on a computer screen. When he moves his eyes the way he's supposed to, he gets a droplet of Tang as a reward.

It occurred to me that Pepper had been lucky. She'd spent her life roaming an 82-acre farm in Slatington, Pa., with a mate, Fred. (They even had a litter of puppies.) Her time at Montefiore Hospital in the summer of 1965 would last all of one day: After a single night spent locked in the rooftop kennel, she was brought downstairs, anesthetized, and killed.

Clayton was born in a breeding center; he grew up in metal boxes and spent his adolescence with a hole in his head and a coil around his eye. In 10 or 15 years of life, he suffered through multiple surgeries and infections and endless hours of restraint in a plastic chair. And for what? Pepper's death, at least, contributed to the development of the cardiac pacemaker—a revolutionary medical device that would prolong millions of lives. Every hour of Clayton's existence has been spent, and will continue to be spent, in the service of basic science.

"Yep, he's still going strong," my former mentor said when I returned from the monkey room. We stood outside a recording chamber, where another animal now sat in front of the monitor. Some people might not like the idea of a monkey working so long, he continued; they say it's better to use each lab animal for one experiment only or a series of related ones … but all the experiments in a given lab are at least somewhat related. "You could easily argue," he added, that the resources necessary to buy and train a new monkey would be a net minus for animal welfare. Why should we euthanize Clayton and start over? Isn't it better for science, and more humane, to use just one animal?

That sort of moral calculus had driven me away from animal research. (I quit in 2003 after a grisly series of experiments involving a suction tube, a scalpel, and the exposed brains of a half-dozen small birds.) Does the cumulative suffering of one animal over 10 years amount to more than the summed misery of several others, used only briefly? Are we trying to reduce the total amount of pain inflicted on animals or the total number of animals killed? Now it seems to me we've grown ever more removed from these sorts of questions.

The development of animal protections has surely reduced suffering in the laboratory. Yet our safeguards have also served to quarantine the ethical debate. The protocols for painful experiments are approved by institutional committees, and the welfare of lab animals has become a topic for obscure scientific measurements. Few outside science get to see what happens inside the laboratory or consider its costs and benefits. (My recent visit with Clayton was itself unusual; primate labs are rarely so welcoming to members of the press.

Pepper brought us through the laboratory door 40 years ago and generated enough public engagement to pass the Animal Welfare Act. Someone's pet—a member of the family—had gotten lost in the enormous enterprise of biomedicine, and we all went in after her. But scientists today no longer need to pluck stray dogs from country roads. Today's lab animals are professionals—life-long civil servants like Clayton, toiling away in the back rooms of a public institution; or else they're disposable commodities, like the millions of rats and mice that ship out from breeding centers every year. Theirs is a closed ecosystem of universities, hospitals, and breeders—a world behind doors with electronic locks.

Will anyone bother to look inside?

Correction, June 9, 2009: This article originally referred to Pavlov's discovery that "animals would drool at the sound of a bell." That's a widely held misconception about his work. It was already well-known that animals could learn to salivate in response to sounds; Pavlov helped elucidate the meaning and function of these conditioned reflexes. References to a "bell" in his work are the result of a long-standing mistranslation from the Russian of the word for "electrical buzzer." In fact, Pavlov only used a bell once or twice in more than 30 years of research. (Return to the corrected sentence.)

Correction,June 11, 2009: The original version described iron supplements as a cure for pernicious anemia. It was the vitamin B12 in liver that served as the basis for Whipple's cure. His experimental dogs did have an iron deficiency, however.) (Returnto the corrected sentence.)